[llvm/dwarfdump] Use the architecture string to filter.

[JDevlieghere]

Summary

Currently dwarfdump uses the ArchType to filter out architectures, which is problematic for architectures like arm64e and x86_64h that map back to arm64 and x86_64 respectively. The result is that the filter doesn't work for these architectures which is usually the reason to use the filter in the first place.

Instead, we should match the architecture based on the string name. This means the filter works for the values printed by dwarfdump. It has the unfortunate side effect of not working for aliases, like AArch64, but I think that's worth the trade-off.

rdar://53653014

[JDevlieghere]

Add test

[merge_guards_bot]

Build result: pass - 60660 tests passed, 0 failed and 726 were skipped.

Log files: console-log.txt, CMakeCache.txt

[aprantl]

Yeah I don't think much value is lost here. Thanks!

llvm/test/tools/llvm-dwarfdump/AArch64/arch.ll

 ; RUN: llc -O0 %s -filetype=obj -o %t.o
 ; RUN: llvm-dwarfdump -arch arm64   %t.o | FileCheck %s
-; RUN: llvm-dwarfdump -arch aarch64 %t.o | FileCheck %s
 ; RUN: llvm-dwarfdump -arch 0x0100000c %t.o | FileCheck %s
 ; CHECK: file format Mach-O arm64
 ;
 ; RUN: llvm-dwarfdump -arch i386 %t.o \
 ; RUN:    | FileCheck %s --allow-empty --check-prefix=NEGATIVE
 ; RUN: llvm-dwarfdump -arch 0 %t.o \
 ; RUN:    | FileCheck %s --allow-empty --check-prefix=NEGATIVE
 ; NEGATIVE-NOT: file format

llvm/tools/llvm-dwarfdump/llvm-dwarfdump.cpp

if (auto *MachO = dyn_cast<MachOObjectFile>(&Obj)) {
     for (auto Arch : ArchFilters) {
       // Match architecture number.
       unsigned Value;
       if (!StringRef(Arch).getAsInteger(0, Value))
         if (Value == getCPUType(*MachO))
           return true;
 
       // Match as name.
-      if (MachO->getArchTriple().getArch() == Triple(Arch).getArch())
+      if (MachO->getArchTriple().getArchName() == Triple(Arch).getArchName())
         return true;
     }
   }
   return false;
 }
 
 using HandlerFn = std::function<bool(ObjectFile &, DWARFContext &DICtx, Twine,
                                      raw_ostream &)>;